In commonly owned U.S. Pat. No. 3,983,685 there has been described a yarn-twisting apparatus of this type in which a thread drawn off a stationary yarn package or spool, centered on an upright axis, is pulled into the open top of a hollow spindle forming part of a thread-guiding structure that is centered on that axis and traverses a spool-supporting platter. The thead exits through a generally radial outlet in a payoff disk, secured to the spindle beneath the platter, and then rises along the inner wall surface of a stationary balloon-limiting cylinder surrounding the yarn package with clearance. An applicator tube, projecting toward a peripheral groove of the payoff disk, contains a wick dipping into a reservoir of treatment liquid, such as water, with which it wets the thread passing periodically across the tip of the tube.